SOLIDWORKS PDM Add-In Registration Error – Failed to extract add-in from <Path> Class not registered
- Authored by Amen Jlili
- Updated June 10, 2025
- Published
- Topics covered: solidworks pdm
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If you’re haunted by a persistent error when loading your SOLIDWORKS PDM add-in, you’re not alone. One of the most common causes of this issue is how the associated processes are launched — particularly when run with elevated permissions.
The Root Cause
SOLIDWORKS PDM can run from several processes, such as:
sldworks.exe(SOLIDWORKS)explorer.exe(Windows Explorer)Inbox.exe(PDM Inbox)Search.exe(PDM Search)
When any of these are launched as Administrator, they run with elevated privileges — a different User Access Control (UAC) level than normal. This mismatch causes unexpected behavior, one of which is the failure to load PDM add-ins correctly.
Even if your add-in DLL is built correctly and deployed properly, the add-in may simply not appear or fail silently when this UAC conflict exists.
Solution 1: Run as a Local User (Not as Administrator)
The most reliable fix is also the simplest:
Always run SOLIDWORKS, Windows Explorer, or any PDM-related process as a standard user — not as Administrator.
If you’re using shortcuts or launch scripts, ensure they’re not set to “Run as administrator.” You can right-click the executable, go to Properties > Compatibility, and make sure “Run this program as an administrator” is unchecked.
Solution 2: Clear Add-in Cache from Local App Data
Another potential fix — especially when you’ve previously had add-in registration issues or made frequent changes during development — is to clear out the cached add-in data.
Here’s how:
- Open the following folder:
C:\Users\<YourUsername>\AppData\Local\SolidWorks DPM\Plugins\<VaultName> - Delete everything in that folder. These are just cached files and will regenerate when PDM starts up again.
⚠️ Important: Be sure to close any PDM-related processes (like Windows Explorer or SOLIDWORKS) before clearing this folder.
Still Stuck? We Can Help
If you’re still running into issues or need professional help developing or debugging SOLIDWORKS PDM add-ins, feel free to reach out. At Blue Byte Systems, we specialize in advanced PDM automation and custom development.
Contact us to learn more.